Evaluation and Management of Pancreatic Cystic Lesions
Journal of Clinical Outcomes Management. 2015 December;22(12)
References
• How are MCNs diagnosed and managed?
Approximately 95% of MCNs are located in the body or tail of the pancreas [67]. These lesions do not communicate with the pancreatic ducts unlike IPMNs, though they may still cause ductal obstruction and dilation [29]. They are often one large unilocular cyst with a thick cyst wall, but in 20% of cases they can have multiple septations [29]. Peripheral eggshell calcification on CT is present in roughly 25% of cases, which is sometimes helpful in differentiating these lesions from serous cystic neoplasms, which often have central calcification [69].
When diagnosed, MCNs are surgically removed [6,14]. A recent surgical series found that the rate of high-grade dysplasia in resected specimens was 5.5%, and the risk of invasive disease was 4.4% [70]. This data suggests that a more conservative approach of observation rather than immediate resection may be reasonable for some patients [70]. The prognosis is very good after MCN resection, with a 5-year survival of 97% to 100% for all comers [68,70]. However, invasive MCNs have a lower 5-year survival rate ranging from 15% to 75% [70,71]. Per the AGA guidelines, patients with invasive disease or dysplasia should undergo yearly surveillance with MRI [14]. This recommendation is based on a potential field defect described with IPMNs. However, the international consensus guidelines only recommends surveillance if invasive disease is present [6,68,71,72].
Case 5
A 59-year-old male presents for evaluation of sudden onset abdominal pain and an 8-pound weight loss over the past few months. Seven years ago a pancreatic cyst was diagnosed and has since been observed by serial imaging. His lipase was 400 U/L (normal < 82) with normal liver function tests. A CT scan of the abdomen and pelvis showed peri-pancreatic stranding consistent with pancreatitis and a large complex cyst in the head of the pancreas.
After the acute pancreatitis resolved, a CT pancreas protocol was performed for better characterization of the cyst. This showed a 5.9 x 5.3 x 1.5 cm, multiloculated cystic lesion without mural nodules, with multiple additional subcentimeter lesions. He underwent an EUS, which confirmed the CT findings ( Figure 5 ). FNA was performed and the cytology showed “paucicellular fluid” and the CEA was 0.9 ng/mL. Due to his weight loss and presentation with pancreatitis, a Whipple procedure was performed and pathology showed a serous cystic neoplasm.
• What is the epidemiology of SCNs and how do they present?
SCNs are benign non–mucin-producing cystic lesions that are characterized by a glycogen-rich epithelium on histology [73]. Of patients with SCNs, 74% are female, with a median age 58 [10]. When diagnosed, most patients are usually asymptomatic (61%), but 27% present with abdominal pain. Other symptoms include jaundice, pancreatitis, nausea, and presence of a palpable abdominal mass. SCNs are more common in patients with von Hippel-Lindau syndrome [74].
• How are SCNs diagnosed and managed?
These cysts have fairly even distribution when discovered in the pancreas [53]. About 74% of lesions have smaller micro-cystic components [75]. About 20% of lesions have a characteristic honeycomb appearance, which is highly suggestive of an SCN [76]. About 30% of patients have a characteristic central stellate scar on CT which is also highly suggestive of an SCN [76]. Unlike mucinous neoplasms, peripheral calcification is usually not seen [69].
